Tendon tissues are highly prone to injury often resulting in the development of tendinopathy Therefore tendon regeneration has emerged as promising therapeutic strategy for tendinopathy The classic method to control tendon cell differentiation is the application of soluble factors to wound site for healing and induction of tendon repair In addition to these soluble cues growing evidence has implied physical cues such as geometric control is capable of directing stem cell commitment to tendon lineage Unfortunately there is no available biomedical tool which can properly control cell shape without disturbing other cellular behavior One of the methods to control cell geometry is micropatterning which has been widely used to control cell shape to regulate stem cell fate We therefore hypothesize that changes of cell shape regulate tenogenesis To confirm this hypothesis we performed tendon stem progenitor cells (TSPCs) to establish tenogenesis in extracellular matrix-coated line patterning to investigate tenogenesis by different geometric controls in vitro We found that TSPCs exhibited proliferation ability and expressed surface markers which were similar to mesenchymal cells These TSPCs grown on 20-100/50-100 μm line pattern expressed tendon markers scleraxis (SCX) and tenomodulin (TNMD) without soluble factor stimulation TSPCs grown on line pattern showed decreased nucleus area and increased aspect ratio To further elucidate the molecular mechanisms we found that Rho kinase inhibitor Y27632 actin cytoskeleton inhibitors cytochalasin D and myosin inhibitor blebbistatin disrupted the F-actin organization and hampered SCX and TNMD expression in TSPCs on line pattern suggesting an involvement of Rho-mediated actin organization in tenogenic differentiation Lastly using microppatterned surface with different aspect ratios we discovered that tenogenesis was found in elongated cells More importantly integrin signaling also played significant roles in tenogenesis via manipulating integrin b1 expression and inhibition of focal adhesion kinase activity Together this microenvironmental cue can regulate TSPC tenogenesis and may provide us a basic understanding of how geometry controls tenogenesis
Shape control of tenogenesis
方妤, 羅. (Author). 2017 7月 19
學生論文: Master's Thesis